Monthly Archives: June 2011

It’s been in the 30s today, and my A/C is not working – looks as though there is some sort of start capacitor which has blown [yup! Simple fix, but still $110 – but no consequential damage], because the fan won’t start without help. I’m just wondering how long it has been running this way, and if there has been consequential damage to the rest of the unit. When I manually start the fan (by carefully spinning the blades) the fan keeps running, but there is no cool air coming out of the AC vents. I guess I’ll find out soon, as the HVAC folks are due for a maintenance check at the end of the week. That’s my hot and miserable start to the week.

Meanwhile, I’m just back from a visit with my daughter in Southern California. While I was there I happened to see that the Riverside Telescope Makers Conference (RTMC) was being held over the US’ Memorial Day weekend. I was due to jump on the plane home on Saturday, but I went up to the site on Wednesday and stayed until early Friday morning.

The weather was dry and pleasant during the day, and downright cold during the night. I fired up the new Astrotrac and took a few exposures, mostly of the region around Vega and a little south of Antares. There was a hulking great mountain to the south, so I didn’t see much point in trying for the southern sky. This was an impromptu exercise, and I wasn’t well prepared.

I was able to set up and align reasonably well. The first night I learned that it was better to set up with the tripod legs fully extended, as trying for a minimal extension resulted in greater stability but an aching back. I ran two image sequences up to about 1 am, but packed up when the wind picked up. I have no idea what the actual wind speeds were, but 50 mph gusts had been predicted, and it certainly sounded as though that was what came through.

The following night I set up with full extension and was much more comfortable in both the alignment and object selection processes. Unfortunately the second night I was exhausted – didn’t sleep well – and quit after only one image sequence.

Since I hadn’t expected to be observing – and certainly not imaging – I had nothing to process the images I captured, and didn’t have any capture software with me either. I captured using an intervalometer I had in my gadget bag, and didn’t capture any darks or flats. I don’t expect the final images to be impressive, but in any case I will post them when I have had a chance to stack them and remove the sky glow.

Shooting at f/4 and ISO 800, I felt comfortable with 4 minute exposures, but not at 5 minutes. Stars were nice and round after a couple of alignment tweaks, and I took sequences of 20 or so each time the Astrotrak fired up. I’m happy with that.

I was shooting with a 70-200 and a 24-105 lens, each with L glass, but I will have to check the EXIF data to see what the nominal focal lengths were for each series.

Seeing wasn’t great on either night, but I thought it was a little better the second night. Skies were fairly good, but I think Starfest skies are a little better. There was a bit of a light dome to the NNE (Las Vegas?) and on the second night another observer complained about the light dome from San Diego (?) to the SSE. The mountains seemed to do a fairly good job of blocking the lights of the greater Los Angeles area, but there was a lot of sky glow along the entire horizon. The site is just barely a borderline green zone on the sky pollution maps, while Starfest, as I recall it, is solidly green.

I’ll try to plan a little better next year so that I can attend the entire event (I missed the swap meet and just about all the vendors, which I normally enjoy at Star Parties). I also have permission to purchase equipment and leave it with my daughter, so I should be able to do more next time. It was a tiring event for me, but considering it was all catch-as-catch-can, I’m pretty satisfied with the way things went.

P.S. Access to the event site is via California Highway 38, a twisting little road full of hairpin turns with breath-taking drop-offs waiting for you if you take them too fast. White-knuckle driving for me, but long-time attendees told me “you get used to it.” Eek!